SOLEHAH BINTI MD HASHIMdifabrikasi di Teknologi QDOS Sdn Bhd. Tiga ujian dijalankan iaitu; 1) Ujian...
Transcript of SOLEHAH BINTI MD HASHIMdifabrikasi di Teknologi QDOS Sdn Bhd. Tiga ujian dijalankan iaitu; 1) Ujian...
LOW POWER HEATER DESIGN ON
FLEXIBLE PRINTED CIRCUIT BOARD
FOR INCUBATOR APPLICATION
SOLEHAH BINTI MD HASHIM
UNIVERSITI SAINS MALAYSIA
2018
LOW POWER HEATER DESIGN ON FLEXIBLE PRINTED CIRCUIT
BOARD FOR INCUBATOR APPLICATION
by
SOLEHAH BINTI MD HASHIM
Thesis submitted in fulfilment of the
requirements for the degree of
Master of Science
May 2018
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ACKNOWLEDGEMENT
In the name of Allah, The Exalted in Might who granted me the strength, eased
my way through this life and provided me patience and courage to complete this thesis as
a fulfilment for my Master of Science in Electrical and Electronic Engineering. This
dissertation is dedicated to everyone in this research who embarks the journey of
expanding the collection of knowledge and transcendent passion for continuous
improvement of the low power electronic device.
First and foremost, I would like to express my gratitude to Associate Prof Dr Zaini
Abdul Halim, my thesis advisor and project supervisor for seeing the promise of this
thesis and achieving my research conducted under her supervision. Her advice, patience
and guidance were pushing factor for my success. Besides, her insightful advices and
invaluable suggestions are much appreciated.
My special thank reached out to the master students, Umadevi Chandaran, Tan
Earn Tzeh, for their helpful support and idea during completion of this project. They
shared their ideas and knowledge on skills and technique which helped me a lot to
understand deeply in this project. My gratitude also goes to SEE staffs for their kindness
and support during my lab experiment.
In addition, my regards and blessing goes to my beloved parents, Md Hashim Bin
Md Tahir and Khamidah Binti Abdul Aziz, siblings and other family member for their
endless love, prayers and support in every aspect. All of your kindness gave me strength
and motivation throughout this journey. This project was supported by the CREST grant.
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TABLE OF CONTENTS
Page
ACKNOWLEDGEMENT ii
TABLE OF CONTENTS iii
LIST OF TABLES vi
LIST OF FIGURES vii
LIST OF ABBREVIATIONS x
LIST OF SYMBOLS xi
ABSTRAK xiii
ABSTRACT xv
CHAPTER ONE: INTRODUCTION
1.1 Research Background 1
1.2 Problem Statement 3
1.3 Research Objectives 3
1.4 Research Scope 4
1.5 Thesis Layout 5
CHAPTER TWO: LITERATURE REVIEW
2.1 Introduction 7
2.1.1 Phase Change Material 7
2.1.2 Lamp and Light Bulb 8
2.1.3 Heating Wire 8
2.2 Application of Flexible Heater 11
2.3 Resistive Heating of Flexible Heater 12
2.4 Power Consumption of Flexible Heater 16
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2.5 Series and Parallel Heater 16
2.6 Heat Transfer of Heater 16
2.6.1 Natural Air 18
2.6.2 Forced Air 19
2.7 Temperature Range of Incubator 19
2.8 Temperature Control System 21
2.9 Summary 21
CHAPTER THREE: METHODOLOGY
3.1 Introduction 22
3.2 Design of Flexible Heater 24
3.3 Fabrication of Flexible Heater 30
3.4 Preliminary Test of Flexible Heater 32
3.5 Development of Incubator 33
3.5.1 Casing 33
3.5.2 Kernel 34
3.5.3 Control System 36
3.6 Testing and Data Collection 42
3.7 Summary 46
CHAPTER FOUR: RESULTS AND DISCUSSION
4.1 Introduction 47
4.2 Functionality Test 48
4.2.1 Single Heater 48
4.2.2 Parallel and Series Heater 52
4.3 Parallel and Series Configuration in Kernel Incubator 56
4.3.1 Result of Heating Process of Heater 56
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4.3.1(a) Temperature 57
4.3.1(b) Temperature Difference 59
4.3.1(c) Temperature Increment 61
4.3.1(d) Comparison of Parallel and Series Heater 64
4.3.2 Result of Cooling Process of Heater 67
4.3.2(a) Temperature 67
4.3.2(b) Temperature Difference 69
4.3.2(c) Temperature Decrement 71
4.4 Incubator Testing 75
4.4.1 Temperature 75
4.4.2 Switching time 80
4.4.3 Power Consumption 82
CHAPTER FIVE: CONCLUSIONS AND FUTURE WORK
5.1 Conclusions 87
5.2 Research Contribution 89
5.3 Future Works 89
REFERENCES 90
APPENDICES
Appendix A: Diagram
Appendix B: Programming
Appendix C: Datasheets
LIST OF PUBLICATIONS
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LIST OF TABLES
Page
Table 2.1 Summary of heater 9
Table 3.1 Summary of the required power to heat up the heater 28
Table 3.2 List of component for electronic circuit 40
Table 4.1 Temperature data of single heater 49
Table 4.2 Characteristic of single heater 51
Table 4.3 Temperature data of parallel and series heater 53
Table 4.4 Temperature difference of heater during heating process 59
Table 4.5 Percentage of temperature difference during heating process 60
Table 4.6 Temperature increment of heater 61
Table 4.7 Calculation of power and temperature increment 62
Table 4.8 Definition of four factors 64
Table 4.9 Temperature difference of parallel heater during cooling process 70
Table 4.10 Temperature difference of series heater during cooling process 70
Table 4.11 Temperature decrement of heater 72
Table 4.12 Calculation of power and temperature decrement 74
Table 4.13 Temperature data of 8.0W in switching mode 76
Table 4.14 Temperature data of 9.0W in switching mode 77
Table 4.15 Temperature data of 10.0W in switching mode 78
Table 4.16 Switching time of heater 81
Table 4.17 Power consumption of heater 83
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LIST OF FIGURES
Page
Figure 2.1 Electrical and thermal properties of heater materials 14
Figure 2.2 Heat transfer of heater 17
Figure 2.3 Metabolic rate graph of human baby temperature 20
Figure 3.1 Flowchart of the project development 23
Figure 3.2 The dimension of heater 26
Figure 3.3 Full view of geometric model for flexible heater 29
Figure 3.4 Close view of geometric model for flexible heater 29
Figure 3.5 Drawing of two strips of heater with copper layer 29
Figure 3.6 Fabrication process of flexible heater 30
Figure 3.7 (a) Full view of flexible heater 32
Figure 3.7 (b) Close view of flexible heater after fabrication 32
Figure 3.8 (a) Series heater connection 32
Figure 3.8 (b) Parallel heater connection 33
Figure 3.9 Drawing of the incubator prototype 34
Figure 3.10 Technical drawing of kernel prototype 35
Figure 3.11 LM35 temperature sensor 36
Figure 3.12 Fan attached to kernel 36
Figure 3.13 Arduino Microcontroller 37
Figure 3.14 Control System using Arduino Uno controller 38
Figure 3.15 Module of L298N 39
Figure 3.16 The flow of the program 41
Figure 3.17 Flexible heater test 42
Figure 3.18 Heater testing with fan 43
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Figure 3.19 Experiment setup to collect data from the kernel of the incubator 43
Figure 3.20 (a) Flowchart of the heater testing without fan 43
Figure 3.20 (b) Flowchart of the heater testing with fan 43
Figure 3.21 Flexible heater with fan and switching control test 45
Figure 4.1 (a) Full view of single heater after fabrication 48
Figure 4.1 (b) Close view of single heater after fabrication 48
Figure 4.2 Current and voltage versus power of single heater 50
Figure 4.3 Resistance versus temperature of single heater 50
Figure 4.4 Power versus temperature of single heater 51
Figure 4.5 (a) Full view of flexible heater after fabrication 52
Figure 4.5 (b) Close view of flexible heater after fabrication 52
Figure 4.6 Current and voltage versus power of series heater and parallel heater 54
Figure 4.7 Resistance versus power of series heater and parallel heater 55
Figure 4.8 Temperature versus power of series heater and parallel heater 56
Figure 4.9 Temperature profile of heater during heating process 58
Figure 4.10 Temperature increment versus power 63
Figure 4.11 Two Way Anova analysis 65
Figure 4.12 Temperature mean analysis 66
Figure 4.13 Fan mean analysis 66
Figure 4.14 Interaction plot for temperature difference 67
Figure 4.15 Temperature profile of heater during cooling process 68
Figure 4.16 Temperature decrement versus power 73
Figure 4.17 Prototype of incubator 75
Figure 4.18 Temperature profile of heater for switching control system 79
Figure 4.19 Switching time versus power 82
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Figure 4.20 Power consumption versus power on 85
Figure 4.21 Average percentage of power reduction 86
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LIST OF ABBREVIATIONS
FPC Flexible Printed Circuit
PC Personal Computer
LCD Liquid Crystal Display
PCM Phase Change Material
SOI Silicon on Insulator
AFM Atomic Force Microscopy
UV Ultraviolet
LED Light Emitting Diode
PVC Polyvinyl Chloride
RTD Resistance Temperature Detector
IDE Integrated Development Environment
ANOVA Analysis of Variance
PWM Pulse Width Modulation
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LIST OF SYMBOLS
R Resistance, Ω
Ro Initial Resistance, Ω
∆R Difference of Resistance, Ω
α Temperature Coefficient of Resistance, /°C
V Voltage, V
I Current, A
ρ Resistivity, Ωm
Ti Initial temperature, °C
Tf Final temperature, °C
Twall Wall temperature, °C
Theater Heater temperature, °C
∆T Difference of temperature, °C
cm Centimeter
μ Micrometer
W Watt
Q Heat Energy, J
c Specific Heat Capacity, J/gK
θ Temperature increment, °C
P Power, W
t Time, s
m Mass, g
h Heat transfer coefficient, W/m2K
s Width, m
d Thickness, m
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l Length, m
A Area, m2
D Density, kg/m3
Dcopper Density of copper, kg/m3
V Volume, m3
Rseries Series resistance, Ω
Rparallel Parallel resistance, Ω
H0 Null hypothesis, Ω
H1 Alternate hypothesis, Ω
μ Mean
α Threshold value
ton Time taken during heating, s
toff Time taken during cooling, s
tswitching Switching time
Pon Power on, W
%P Percentage of power,%
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REKA BENTUK PEMANAS KUASA RENDAH DI ATAS
PAPAN LITAR TEKAP FLEKSIBEL BAGI APLIKASI INKUBATOR
ABSTRAK
Inkubator adalah peralatan yang digunakan untuk membina dan mengekalkan
persekitaran yang stabil bagi bayi, telur, haiwan, sel dan organisma hidup. Kebiasaannya,
inkubator yang digunakan dalam saiz yang besar, berat dan menggunakan kuasa yang
tinggi. Oleh sebab itu, pemanas fleksibel yang nipis dan ringan dicadangkan untuk
merekabentuk inkubator yang ringan dan cekap tenaga. Walaubagaimanapun, pemanas
fleksibel hanya terdapat dalam sambungan sesiri yang mungkin menyebabkan
penggunaan kuasa yang tinggi. Oleh itu, pemanas fleksibel dalam konfigurasi selari dikaji
dalam projek ini. Pemanas direka menggunakan perisian Ansys dan dimensi untuk
pemanas tersebut ialah 1.62m (panjang), 0.33m (lebar) dan 35μm (tebal). Pemanas
difabrikasi di Teknologi QDOS Sdn Bhd. Tiga ujian dijalankan iaitu; 1) Ujian fungsi
pemanas tunggal, pemanas sesiri dan pemanasan selari, 2) Ujian pemanas sesiri dan selari
dengan dan tanpa kipas dalam inkubator, 3) Pemanas sesiri dan selari dengan dan tanpa
kipas menggunakan sistem kawalan bertukar dalam inkubator. Mikropengawal yang
digunakan dalam projek ini ialah Arduino Uno. Keputusan menunjukkan semasa proses
pemanasan, pemanas sesiri dengan kipas dan selari dengan kipas boleh mengurangkan
kuasa sebanyak 12.5% dan 13.8% berbanding dengan pemanas sesiri tanpa kipas dan
pemanas selari tanpa kipas. Keputusan juga menunjukkan pemanas sesiri tanpa kipas dan
pemanas selari tanpa kipas dapat mengurangkan tenaga sebanyak 6.37% dan 16.9%
semasa proses penyejukan. Oleh itu, bagi proses penyejukan, pemanas tanpa kipas adalah
lebih baik daripada pemanas dengan kipas. Dalam ujian ketiga, keputusan menunjukkan
bahawa pemanas selari dengan kipas semasa proses pemanasan dan pemanas selari tanpa
kipas semasa proses penyejukan menggunakan sistem kawalan bertukar dapat
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mengurangkan kuasa sebanyak 48.66% berbanding pemanas lain. Kesimpulannya,
pemanas selari yang dicadangkan menggunakan kuasa yang lebih rendah dan sesuai untuk
aplikasi inkubator.
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LOW POWER HEATER DESIGN ON FLEXIBLE PRINTED
CIRCUIT BOARD FOR INCUBATOR APPLICATION
ABSTRACT
Incubator is equipment used to grow and maintain a stable environment for infants, eggs,
animals, cell and living organism. Conventionally, the incubators are commonly bulky,
heavy and high power consumption. Therefore, a flexible heater is proposed to design a
light-weight and power efficient incubator. However, flexible heater is only available in
series connection, which may cause high power consumption in incubator. Therefore,
flexible heater in parallel configuration is studied in this project. The heater is designed
using Ansys software and dimensions for the heater is 1.62m (length), 0.33m (width) and
35μm (thickness). The heater is fabricated at QDOS Technology Sdn Bhd. Three tests are
conducted which are; 1) Functionality test of single heater, series heater and parallel
heater, 2) Series and parallel heater with and without fan test in the incubator, 3) Series
and parallel heater with and without fan test using switching control system in incubator.
Microcontroller is used in this project. Results show that for heating process, series heater
with fan and parallel heater with fan can save more power by 12.5% and 13.8% compared
to series heater without fan and parallel heater without fan. Results also show that the
series heater without fan and parallel heater without fan can reduce power by 6.37% and
16.9% during cooling process. Therefore, for cooling process, heater without fan is better
than heater with fan. In the third test, results show that by using switching control the
parallel heater with fan at heating stage and the parallel heater without fan at cooling stage
can reduce power by 48.66% compared to other heaters. As a conclusion parallel heater
consumes less power and suitable for incubator application.
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CHAPTER ONE
INTRODUCTION
1.1 Research Background
An incubator is a device used to grow and provide humidity, temperature and
oxygen for infants, eggs, animals, cell and living organism. The simplest incubator
consists of boxes or container with an adjustable heater and the most commonly used
temperature for bacteria and mammalian cells is approximately 37°C. Incubators are
usually run on electricity with size ranging from small table top unit to room-size.
The history of incubator started in late of 18th century when the first published
description of incubator was written by Denuce. In 1883, a French obstetrician Stephane
Tarnier invented the first infant incubator to warm numerous premature infants in Paris’s
Maternite´ hospital. This incubator was made using hot water reservoir attached to an
external heating source. This hot water bottles were replaced manually every 3 hours. In
1891, Alexandre Lion was invented more sophisticated incubator than Tarnier. He
designed an infant incubator with a large metal apparatus equipped with a thermostat and
an independent forced ventilation system. Then, a Chicago obstetrician Joseph B. Dee
Lee was created a transport service using portable incubator to pick up the premature
new-born in Chicago in 1990 (Baker, 2000). Dee Lee’s invention encouraged Julius Hess
developed the first electrical heated bed surrounded by metal jacket containing hot water
(Ehsan, et al. 2011). Since then, there are many more types of incubator came out such as
manually controlled incubator, servo-controlled incubator, open box-type incubator,
close type incubator and portable incubator.
Nowadays the portable incubator is important since people are moving all over
the world. Hence, the design of the portable incubator should be rugged in casing, safe
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for air travel, sensitive to temperature control and inexpensive (Charles, 1968). The
portable incubator also should consume less power and not heavy. Unfortunately, the
conventional incubators are often heavy, bulky and immobile (Walzik, et al. 2014).
The incubator consists of heater component, control system and power supply.
Electrical heater is commonly used in the incubator. It converts electrical energy to heat
energy through Joule Heating concept where the heat is produced due to the flow of
current within the heater. There are many type of heater design where the design comes
with specific application such as light bulb in chicken incubator and heating wire in infant
incubator. The selection of the heater depends on the heater material, heater types, sheath
material that surrounds the heater and the operating voltage of the heater. Example of
heater types are strip, ring, rope and cable, cartridge, tubular, band, immersion,
circulation, process air and duct, radiant, comfort, flexible, tote, and drum.
Today, flexible heater has become popular and available in market. The
advantages of using flexible heater are it can be bent which can be designed in specific
shape which makes it suitable for cylindrical devices. Flexible heater provides fast heat-
up and cool down rates, uniform heat distribution and high watt densities (Radadia, 2008).
The heat transfer of flexible heater is good due to direct bonding and heater's thin design.
In incubator most of the heat is transferred through conduction and convection process
inside the incubator. In heater, the heat is transferred through conduction process. When
the adjacent atom or molecules in the heater vibrate and interact with the adjacent atoms
or molecules, heat energy will be conducted to the neighbouring particles. This will make
the whole heater become hot. Meanwhile, the heat from the heater is transferred to the
surrounding incubator through convection process by movement of air inside the
incubator.
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1.2 Problem Statement
In the case that biological samples are cultured at different locations or there are
no culture facilities available, the probes need to be transported to the laboratory which
can cause delays or in the worst case failure of a planned experiment. Thus, making the
incubator small, low power and transportable is a hugely advantage. Most incubators run
on electricity and are rendered worthless in regions without electricity, or in those that
suffer from electricity shortage. The challenge therefore is to design an energy efficient
incubator that will run using low power of electricity. A portable incubator with low
powered heater is addressed on these issues.
Heating rods and coils is widely used as a heating element in the incubator.
However the drawbacks of the heating rods and the heating coils are bigger size and
heavy. Flexible heater is one more available option for electrical heater. The flexible
heater is a resistive heater which offers low cost, thin, lightweight, flexibility, minimum
occupied space and high heating rates. However, the flexible heater may consume a lot
of power because it is connected in series configuration and has high value of resistance
of the heater. Since the power consumption is based on the resistance of the heater and
the length of the heater will determine the resistance of the heater, so there is a possibility
if the length is reduced then the power consumption can be decreased.
1.3 Research objectives
In this thesis, flexible heater in incubator application is studied. The performance
of series and parallel flexible heater is investigated whether it can reduce the power
consumption in incubator system. Besides, the effect of fan and switching control is
studied in incubator application. Therefore, a low power portable incubator is developed
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to test the flexible heater with fan and switching control system. Hence the following
objectives have been set to solve the problems.
i. To identify the performance of parallel flexible heater and series flexible heater
for low power incubator application.
ii. To investigate the effect of fan on the heater performance for incubator
application.
iii. To develop a low power portable incubator by using flexible heater with fan or
without fan and switching control system.
1.4 Research Scope
The study is defined with a few requirements and specification which as listed as
follows:
(a) Engineering specification: Investigate the changes of heater’s temperature and
power from series and parallel heater with fan or without fan. Establish
switching controller to investigate the power of series and parallel heater and
implement the switching control system in incubator.
(b) Hardware specification: A microcontroller PIC based system is developed to
perform data acquisition for the development of incubator system and control
the switching time for heater during heating and cooling.
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(c) Test specification: Evaluate the performance of series and parallel heater in
incubator in terms of temperature, time and power. Performance of series and
parallel heater with switching control and fan is also analysed.
1.5 Thesis layout
The thesis is organised into five chapters. The first chapter discusses on the
background of incubator and problems faced by researchers in conventional incubator.
The overview of flexible heater application as an alternative to the existing heater used in
incubator is also briefly explained. This chapter also discussed on problem statements,
research objectives, research scope and thesis layout.
Chapter 2 explains on literature review whereby it describes the research and
studies of different types of heaters use in various applications. The application of flexible
heater, resistivity, power consumption, types of heaters connections, heat transfer in
incubator and temperature range and control is discussed in detail in this chapter.
The third chapter discusses on work flow of the project. The work flow described
and illustrated by a flow chart and block diagram. A detail explanation of design of heater,
fabrication of heater steps is presented in this chapter. Preliminary test on electrical
characteristics of heater is further discussed. It is followed by development of incubator,
testing and data collection. This chapter is concluded in summary.
Chapter 4 explains about results and discussion from the test. The chapter is
divided into introduction, functionality test, parallel and series configuration test and
switching control test in incubator. The results of temperature and power are studied and
compared for all types of heaters. The explanation also consists of data collection and
graphical analysis.
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Finally, Chapter 5 describes in detail on the conclusion of the research, research
contribution and the suggestions for future works.
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CHAPTER TWO
LITERATURE REVIEW
2.1 Introduction
The previous chapter demonstrated that the incubator plays a major role providing
an appropriate environment for infants, eggs, animals, cell and living organism. This
device is designed to maintain humidity, carbon dioxide and the temperature within it.
Incubators require accurate temperature regulation (Tisa, 2012). The most important part
of the incubator is a heater. The heater produces heat and helps regulate temperature. It is
used for raising and maintaining the temperature of the air surrounding the incubator.
There are many types of heaters such as a Phase Change Material (PCM) heater, lamp or
light bulb heater, heating wire heater and flexible printed circuit heater. The details of
each heater are discussed from Sections 2.1.1 to 2.1.3.
2.1.1 Phase Change Material
A Phase Change Material (PCM) heater uses materials such as water and metal
balls that are incorporated into a container that can store and release heat through the
changing of a liquid phase to solid phase or vice versa. For a PCM heated incubator, the
amount of heat released largely depends on the temperature gradient between the PCM
melting/solidifying points and environmental temperature. The advantages of a PCM
heated incubator are that it is simple, safe and inexpensive. However, there are noticeable
drawbacks. A PCM overheats and becomes increasingly unreliable as the material
degrades through repeated cycles of heating. Besides, the time taken to release absorbed
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heat is too long which takes place over 1 to 2 hours depending on the ambient temperature
(Mishra, et al. 2015).
2.1.2 Lamp & Light Bulb
The attempts to incorporate an electrical heater such as an incandescent lamp or
light bulb in portable incubators are not new. One of the earliest documented applications
of an electrically heated cell culture portable incubator was in 1968 (Charles, 1968). Two
incandescent lamps acting as the heating element are placed in the incubator with a fan
and thermo-regulator. The heaters are connected in parallel and require a minimum of 10
W battery to maintain a temperature of 37° C within the incubator at an ambient
temperature of 5° C. Other types of incubators have used an electrical heater using a lamp
and light bulb, such as egg incubator (Adid, 2008; Adegbulugbe, et al. 2013) and infant
incubator (Singh, 2006; Mittal et al. 2015). However, the net weight of a cell culture
incubator introduced by Charles (1968) is 14.6 kg which it still heavy to carry during
transportation.
2.1.3 Heating Wire
Another type of electrical heater used in incubators is heating wire. In 1978, a
portable neonate incubator was invented by Durie (1978). He used a heating wire that is
bonded to their inner kernel of the incubator wall. The product’s name is the Maxcell
Mini CO2 Incubator and was designed by a company N-Biotek. The incubator design
involved an electric heating wire with a maximum AC voltage of 220 V to cover the six
sides of the chamber. The three parts of the heating section are controlled and calibrated
individually by three temperature sensors (Durie, 1978). However, this product is not